This invention relates to a system of accuracy checking of the weight of objects measured by vibratory weighers (examples being weigh belts or the Magna Weigh® product as described in U.S. Pat. No. 5,780,780).
This application incorporates all material described in U.S. Pat. No. 5,780,780 (the '780 patent) issued on Jul. 14, 1998 to the applicant, the contents incorporated by reference.
It is often desirable to use vibratory weighers to measure the weight of a stream of bulk product. Variable speed conveyors have been used for this purpose, flow rate control being obtained by measuring the weight of objects as they are being transported on a conveyor of known length.
For example, vibratory weighers are transporting, for example, foodstuffs being unpackaged, peeled, cut or otherwise processed to expose edible surfaces (hereinafter “raw foodstuffs”). It is also particularly important when dispensing measured quantities of objects, for example, to obtain desired proportions by weight of one type of foodstuff to another. Therefore, it is generally desirable to measure the weight of objects, such as raw foodstuffs, on a typical belt type conveyor using a vibratory weigher.
Since vibratory weighers are the preferred method of weighing product that is continuously fed, is important that the vibratory wiegher have the capability of calibration and accuracy checking during operation. In certain situations, such as high volume production facilities, the ability to stop the flow of product, to calibrate the vibratory feeder, may result in considerable production loss.